tests/fakepatchtime.py

revlog: refactor delta chain computation into own function

This code is already written in multiple locations.

While this code needs to be fast and extracting it to its own function
adds overhead, code paths reading delta chains typically read,
decompress, and do binary patching on revlog data from the delta chain.
This other work (especially zlib decompression) almost certainly
accounts for a lot more time than the overhead of introducing a Python
function call. So I'm not worried about the performance impact of this
change.

# extension to emulate invoking 'patch.internalpatch()' at the time
# specified by '[fakepatchtime] fakenow'

from __future__ import absolute_import

from mercurial import (
    extensions,
    patch as patchmod,
    util,
)

def internalpatch(orig, ui, repo, patchobj, strip,
                  prefix='', files=None,
                  eolmode='strict', similarity=0):
    if files is None:
        files = set()
    r = orig(ui, repo, patchobj, strip,
             prefix=prefix, files=files,
             eolmode=eolmode, similarity=similarity)

    fakenow = ui.config('fakepatchtime', 'fakenow')
    if fakenow:
        # parsing 'fakenow' in YYYYmmddHHMM format makes comparison between
        # 'fakenow' value and 'touch -t YYYYmmddHHMM' argument easy
        fakenow = util.parsedate(fakenow, ['%Y%m%d%H%M'])[0]
        for f in files:
            repo.wvfs.utime(f, (fakenow, fakenow))

    return r

def extsetup(ui):
    extensions.wrapfunction(patchmod, 'internalpatch', internalpatch)